The Celsius and Certainty combo is quite popular among the DIY lawn care community. It’s popularity is mostly due to the fact that it can be applied in the heat of the summer with minor bermudagrass impact.
It is recommended to apply when soil temperatures are at least 65°F and daily temperatures are over 80°F. I hit the mark barely. My soil temperatures are fluctuating between 64° and 65° and my daily temperatures in Alabama range from 74°-85°. Not bad, huh?
My primary weed target was burweed, poa annua, and several different clover and broadleaf weeds. The clover and broadleaf were clearly dead after 3 days, the poa in about 5 days, and the burweed was starting to yellow after 7 days.
Keep in mind, Certainty requires that their product mix with at least 2 gallons of water. That’s why it took me 3 fills on a 4 gallon backpack sprayer to cover 6,000 ft². Overall, I am very happy with the results. Granted, as temperatures rise these weeds will die regardless.
Check out my blog for more videos on maintaining a Bermuda lawn.